vice president joe biden and his wife jill, parking 100,000 care packages for the troops overseas. people here in the bay area also intervene conveniented -- intervened. alex savidge has more on this. >> reporter: construction got underway early this morning, a habitat for community, volunteers in hard hats fanned through the in daly city. some painted. >> we're really looking forward to coming together and finding a way to service and really to contribute. >> reporter: about 100 people took part today helping put the finishing touches on this 36 unit complex that will provide affordable housing for bay area families. but -- but those chosen families do have to put up work. they help build the home they will live in. >> reporter: the volunteers started to build this back in 2010. it's the largest habitat for humanity project in the world. rob alvarado working on the roof today was here when construction first started and came back for this national day of service. >> i feel like, you've had a lot of opportunity, you've had success and you just feel fortunate. you should come out an